Square cushion stone



FIG. 1 is a top, front, and right side perspective view of a square cushion stone;

FIG. 2 is a bottom, rear, and left side perspective view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof; and,

FIG. 5 is a side view thereof, all side views being the same.

The broken lines in FIGS. 1, 2, 4, and 5 depict portions of the square cushion stone that form no part of the claimed design. 

CLAIM We claim the ornamental design for a square cushion stone, as shown and described. 